feat(chat): implement sequence pre-allocation, versioned sync, and push worker

Introduce several performance and synchronization enhancements:
- Implement `SeqBufferManager` to allow sequence number pre-allocation via Redis Lua scripts, reducing atomic increment overhead.
- Add `PushWorker` to handle asynchronous message pushing using Redis Streams.
- Implement incremental conversation synchronization via `ConversationVersionLog` to allow clients to fetch only recent changes.
- Add support for Gzip compression in WebSocket communications to reduce bandwidth usage.
- Update dependency injection and configuration to support these new components.

cmd/server/app.go

@@ -28,6 +28,7 @@ type App struct {
 	Publisher       ws.MessagePublisher
 	TaskDispatcher  runner.TaskDispatcher
 	Logger          *zap.Logger
+	PushWorker      *service.PushWorker
 }
 
 // NewApp 创建应用程序
@@ -41,6 +42,7 @@ func NewApp(
 	publisher ws.MessagePublisher,
 	taskDispatcher runner.TaskDispatcher,
 	logger *zap.Logger,
+	pushWorker *service.PushWorker,
 ) *App {
 	return &App{
 		Config:          cfg,
@@ -52,6 +54,7 @@ func NewApp(
 		Publisher:       publisher,
 		TaskDispatcher:  taskDispatcher,
 		Logger:          logger,
+		PushWorker:      pushWorker,
 	}
 }
 
@@ -73,6 +76,11 @@ func (a *App) Start(ctx context.Context) error {
 		a.HotRankWorker.Start(ctx)
 	}
 
+	// 2.2 启动 PushWorker（Redis Stream 异步推送）
+	if a.PushWorker != nil {
+		a.PushWorker.Start(ctx)
+	}
+
 	// 3. 创建 HTTP 服务器
 	addr := fmt.Sprintf("%s:%d", a.Config.Server.Host, a.Config.Server.Port)
 	a.Logger.Info("Starting HTTP server",
@@ -148,6 +156,12 @@ func (a *App) Stop(ctx context.Context) error {
 		a.HotRankWorker.Stop()
 	}
 
+	// 5.1 停止 PushWorker
+	if a.PushWorker != nil {
+		a.Logger.Info("Stopping push worker (stream)")
+		a.PushWorker.Stop()
+	}
+
 	// 6. 关闭数据库连接
 	a.Logger.Info("Closing database connection")
 	sqlDB, err := a.DB.DB()